Variable delivery pump or motor



P 938. E. K. BENEDEK 2,129,642

VARIABLE DELIVERY PUMP OR MOTOR Filed Aug. 3, 1954 3 Sheets-Sheet 1 ELEKBENEIJEK F153 WKWW p 8. E. K. BENEDEK 2,129,642

VARIABLE DELIVERY PUMP OR MOTOR Filed'Aug. 5, 1934 3 Sheets-Sheet 2 F1EZ 3mm ELEKEJENEDEK.

HEELv X47 Sept. 13, 1938. E. K. BENEDEK VARIABLE DELIVERY PUMP OR MOTORFiled Aug. 3, 1934 3 Sheets-Sheet 3 I gwue/wkw ILEK EENEDEK ag JPatented Sept. 13, 1938 UNITED STATES PATENT OFFICE f 2,129,642 VARIABLEDELIVERY PUMP R. MOTOR Elek K. Benedek, Bucyrus, Ohio Application August3, 1934, Serial No. 738,184

14 Claims.

This invention relates to pumps ormotors of the variable delivery radialpiston type and more par ticularly to that type of pumps or motors,wherein the radial piston load is carried by a reciprocating T-head, andthe T-head itself is supported on anti-friction rollers contained in acommon cage and cooperable with the reciprocating crosshead in suchmannerthat said roller assembly is interposed between said reciprocatingcrosshead and a relatively stationary reaction plate or drum which issubstantially parallel with the reciprocating crosshead, whereby saidroller assembly is forced to roll between the parallel track surfaceswhich are in relative reciprocation, thus the roller-cage assembly alsomust perform a relative reciprocation in regard to both of said trackelements. As it is obvious from the kinematics of such combination, thatthe rollers will travel a distance determined by the distance ofreciprocation of the crosshead, which actually results in thereciprocation of the roller-cage assembly relative to the crossheadone-half the distance of reciprocation of the crosshead. The. totalamount of travel of the crosshead in either direction is, of course,equal to the "stroke of the piston at a given stroke setting. In thepumps of this type herein above referred to, there is still slidingfriction between the inner face of the reciprocat ing crosshead andcooperating relatively stationary surface of the polygonal driving headand the driving force is carried only on an oil film, provided by andfrom a spray of operating fluid, which escapes as slip through and fromthe outer ends of the pistons. For the sake of hydraulic efficiencytheescapage of fluid as slip is minimized, as much as possible by closefitting of the pistons and when slip does occur the fluid is, of course,thrown outwardly centrifugally, away from the innermost slidingsurfaces, thus greatly reducing lubrication of these surfaces. Thus thepartial lubrication of the radially inwardly disposed sliding surfacesof the reciprocating crossheads often becomes insufficient towithstandthe twisting effect of the driving torque on the driving cross- 5 headagainst its guiding surfaces and results in gaulding of such slidingsurfaces, thus preventing further reciprocation -of!" the crossheads andv wrecking the 'entire-me'cha'nisin y A further'def e'ct ofabove"referred to roller and '50 cage load transmission lies in the fact thatthere are no mean provided to} positively control the.

roller sau a assemblymm respect to the t and its T- -shap'ed cross-"heed i 55. axisbfsaidbagefand' a" stop screw fastened to furl slot in,the longitudinal View taken on line 2-2 inFig; 1; Y 1

(Cl. 103-161) I the reaction plate or roller track of the rollers. It isevident, that due to the enormous acceleration of the cage and rollerassembly, and the cocking load of the driving rotating force, the cagetends to become displaced from its theoretical dy- 5 namic position withrespect to said stop screw and crosshead so that sooner or later apounding of the cage against said stop takes place which may result inone or more of the rollers leaving the cage, blocking the furtherreciprocation of 10 the crossheads and wrecking the pump.

The inherent faults of such structures as hereinabove referred to arefurther aggravated by the fact, that the leading inner ends of thedriving crossheads, when cocked or tilted by the drivl5 ing torque; atthe contact points of the crosshead create considerable mechanicalfriction, cause loss of useful power, and decrease the efficiency of themachine.

In order to alleviate the above encountered defi- 20 ciencies, I haveprovided a novel pump structure, in which the hydraulic piston load, thetorque forces of the driving couple acting on the crossheads, as well asthe piston actuating forces during the suction cycles are alltaken up ina more 25 efficient manner and by a novel load transmission structure;which structure, while it provides frictionless support for the crossheads in withstanding all three of the previously enumerated forces, isrelatively stationary with respect to the 30 reciprocating crossheadsand therefore may be very rigidly supported.

It will be hereinafternoted that in addition to the improved results andsimplified structure of my novel mechanism, there are several mechan- 35ical features which simplify its manufacture as a precision instrument,in permitting more simple manufacturing expedients, for example,centerless grinding etc.

tion with the accompanying drawings. forming a part of thisspecification.

In the drawings: 3 Fig. 1 is a vertical sectional view of a pump,constructed in accordance with the invention, taken'on line l'-l in Fig.2; f

Fig. 2 is a transverse fragmentary sectional Fig. 3 is a front elevationof my integral T-head solid piston shown separately from the pump toillustrate various forces on the same;

Fig. 4 is a fragmentary sectional view taken on line 2-2 in Fig. 1 witha part of the cheek plate broken away, to show the bearing mounting ofmy novel crosshead operating means, part of the view being taken alongthe line 4a4a in Fig. 5;

Figs. 5 and 6 are fragmentary sectional views of the cheek plate takenon line 66 in Fig. 4, the rollers and their needle bearings beingremoved from the plate in Fig. 6; and

Figs. 7 and 8 are fragmentary sectional views similar to Fig. 4,illustrating two relative positions of the piston and anti-friction loadtransmitting means.

Fig. 9 is a fragmentary cross sectional view of a slightly modified formof bearing for use in connection with the cylinder block.

The mechanism disclosed for illustration is enclosed within a casingcomprising a central body section I and end heads 2 and 3, which arecarefully fitted to the end faces of the cylindrical body portionthrough appropriate shoulders and recesses respectively, to provide forsubstantially permanent alignment for the central axis of the entirecase during the operation of the machine.

The end head 2 is provided with a central hub portion 2" to receive thepump valve, as well as carry the main fluid pipe connections of thepump, for suction and delivery of operating fluid. The end heads havebell-shaped portions 2' and 3' respectively, which are appropriatelyrecessed for rigidly supporting stationary rings I1 of antifrictionbearings l8 for supporting a rotary cylinder block or barrel Ill. Therecesses also provide axial abutment surfaces for the respective bearingrings. The inner bearing rings l6 tightly embrace and axially abutsuitable shoulders on the cylinder barrelthe spaced bearing arrangementforming a balanced and sturdy support for the barrel as well as holdingthe barrel in place against axial shifting.

The cylinder barrel I0 is provided with a plurality of radial bores asat IS in a well known manner for pistons 25, which cylinders are incommunication with main pump ports 2| and 22 respectively through radialports 14, one for each piston cylinder.

An impeller shaft 4 projects through a central bore of the end head 3into the pump casing, terminating inwardly at 1, the inner end portionfitting a tapered bore 8 of the cylinder barrel l0, and being drivinglyrigid therewith through the medium of a feather key 9. A suitablelocknut 6 on the threaded portion 5 of the shaft pulls the taperedsurfaces together to form a very rigid connection between the cylinderbari el and shaft. The tapered and keyed connection is preferably in thetransverse plane of the bearing [8 surrounding the smaller end I 0 ofthe cylinder barrel thereby assuring proper support for the shaft at thezone of application of driving torque to the barrel to the end ofassuring quiet rotation of the cylinder block.

The cylinder barrel l0 adjacent its tapered bore 8, is provided withanother slightly tapered bore as at H to receive the reduced diameterportion IQ of a central valve or pintle 20. The reduced portion of thepintle is tapered in order to limiit the escape of pressure fluidaxially, as

" well'as to prevent air suction around the peripheral surfaces of thepintle. In order to further seal the pintle engaging end of the cylinderbarrel, between the pintle and bore ll of thebarrel,

I provide a circular'fiuid chamber as at l2, by counterboring the blockat I2l3, which chamoer will become filled by pressure fluid escapingfrom the barrel to prevent air suction, during the suction strokes,particularly when the machine is operating as a pump and is set forshort piston stroke service, and also to maintain the desired slippressure. The chamber I2 is constituted by a free uninterruptedclearance space or oilreceiving void between the longer diameter portionor shank of the pintle and the wall of the barrel counterbore l3. Asshown in Figure 1, the pintle shank extends into but terminates short ofthe inner end of the counterbore.

To the end of maintaining such pressure in the chamber l2 and preventsealing fluid loss 'centrifugally, I preferably use, instead of thebearings l8 above noted, a special bearing l8 at this end of thecylinder barrel I0, a detail of which is shown in Fig. 9. This bearingis substantially sealed by a ring plate 49 at one transverse end face,the plate 49 being suitably secured to one race member (IG e. andcontinuously extending into a peripheral groove in the other member (I'le. g.). The ring plate may be snapped into place to assemble it into thebearing. Thus a substantial volume of operating fluid under pressure canbe maintained from the slippage of the pump to prevent sucking air onthe suction strokes of the pistons. This is particularly important afterlong continued service has Worn either the pintle or barrel, and hasincreased the clearance therebetween. The excess slip of pressure fluidleaves the pump casing through a suitable drain orifice 31 in the casingsection I.

Reversible mains of the pump 23 and 24 respectively in the hub portion2" provide for inlet and outlet pipe connections.

The pistons 25 have T-heads 26 rectangular in cross section, integrallysecured to respective pistons proper and adapted to operate the pistonsduringrotation of the piston and cylinder assembly in the followingmanner.

The stroke controlling mechanism comprises a pair of cheek plates 34,one at each side of the reciprocating crossheads supported in the casingsection I by an anti-friction bearing comprising outer ring 33, innerring 30, and a plurality of rollers 3|, caged in an appropriate retainer32, The cheek plates 34 are secured to the inner ring 30 of theantifriction bearing as illustrated in Figs. 5 and 6. It is evident fromthese figures, in connection with Fig. 1, that the outer circumferencesof the plates 34' are recessed to obtain circular axial and radialshoulders 34" and 34, respectively, as better illustrated in Figs. 5 and6 and that the ring 30 is complementarily formed so that the plates maybe assembled thereon as by press fitting onto said surfaces 34" andagainst the shoulders 34. The plates 34 may be retained in theirrespective shoulder seats by screws 42, extending through appropriateholes 4| of the cheek plates into threaded openings of the inner race 30aligned therewith. To facilitate pulling the cheek plates off the pressshoulders of the ring 30 when desired, a few tapped holes may beprovided in the outer flanges of the plates so that screws engaging thethreads may abut the ring surfaces which abut the shoulder faces 34 ofthe plates. Thus it will be seen that a very rigid mounting is securedfor the cheek plates 34, the rigid cheek plate and bearing ring assemblybeing well adapted to b'e' s upported by a more or 4 equal and oppositemoment M2 if equilibrium and posed. inthe central plane of the machinewhich coincides with the axes of the pistons. The bearing shown isadapted for high speed and excessive pressures. The cheek pl'atescloselyembracethe piston crossheads to prevent axial displacement of the cheekplate and bearing ring assembly Thus. the cheek plates "provide radialflanges which, with the ringill, deflne a circumferentially closedtroughfor retaining lubricant.

i Therollersof vthe bearing operate in a suitable annular raceway'in thering. 33 so as not to become axially displaced.

Pursuant. the requirements of a highly special structure of the classdescribed, I further provide as a reactance support for the pistoncrosshead, a plurality of rollers mounted at their ends in therparallelwallsof the cheek plates 34, the

rollers-having their axes parallelto the rotational axis, of the-pump.

A main or load roller 29 is provided in normal radial alignment with thereciprocating piston, as shown in Fig. 4,having somewhat reduced endportions as at 28, said end portions being mounted in heavy duty bearingmeans 21 in axially aligned bores 28' of the cheekplates 34. For thepurpose of illustration, a plurality of small (needle) rollers are usedwithout mechanical cages, and the small rollers are located againstaxial displacement in undercut recesses provided in the roller ends 28.It is understood, however, that any high grade bushing may be usedinstead of the needle rollers 21, to thereby reduce'the price of theunit, and increase its commercial utility, particularly in cases wherethe centrifugal pressure oil bath, confined by the cheek plates 34 andby the inner race 30} is available for ample lubrication of the bearings21, and where exchange and replacement of the rollers 29 may be easilyeffected. The rollers are subject to mass production by centerlessgrinding which cuts their cost to a point where, due tointerchangeability, the needle rollers are not prohibitively expensivefor this class of mechanism. The axial position of each of the rollers29 is secured by having its center portion slightly larger in diameter,than the supporting bores in the cheek plates.

Referring again to Fig. 4, a pair of torque rollers Bit-36 are providedat each end of the relciprocating crosshead 26, the axes of eaeh pair ofthe rollers being disposed in planes parallel to the inner and outercrosshead surfaces respectively and extending parallel to the.rotational axis of the barrel it so as to engage the. crosshead forrolling to and fro therealong tangentially of the path of rotation ofthe T-heads' The reduced end portions of the torque rollers 36 areconstructed as previously.descri'bed-see Fig. 5slightly recessed as at28' to thereby accommodate the needle bearings 21. For convenience, thelarge roller 29 will be'considered'the pressure roller or main roller,due to the fact that its main function is, particularly, to take up thehydraulic pressure of the piston. As will be observed in Fig. .4, themain load will be inherently driving of the reactance rotor are to bemaintained. The moment M2 is provided by the two reactionary forces P2,one such force being exerted by'one outer torque roller 36, and theother force P2 by an inner torque roller 36 at the opposite side of thepiston axis from the first torque roller. This relation to the torquerollers is effected bythe forward cocking of the piston T-headandresultant warping into positive contact with one inner and one outerroller. If the roller 29 wereomitted, the radial outward forces orhydraulic load would have to be resisted by both of the outer rollers36, due to the fact that the Ir-head would bow outwardly, tending tocounteract the engagement with the inner roller 36 produced by thecocking or the head. As a result of such omission, the efiectivepositive driving connection between the crosshead ends 'and the rollers36 could not be provided but reliance would have to be placed on rollingfrictional resistance. The application of hydraulic load pressurereactance by the roller 29 to either side of the piston axis may assistin withstanding the moment M1 or may aggravate the condition slightly,depending upon which side of the piston axis it is disposed at theparticular incident, but

it restrains outward bowing of the piston T-head so that the T-head canwarp and cooperate properly with one outer and one inner roller 36, asdescribed, for providing anti-friction positive torque transmissionbetween the barrel i0 and the reactance rotor; Naturally the functionsof the rollers 29 and 36 are not limited entirely to radial pressure andtorque respectively for the pistons are only aligned with the rollers 29a small portion of the time and the deflection of the crossheads is veryslight, but a preliminary analysis of the operation of my novelcombination suggests a performance as hereinabove outlined.

In regard to the motion of the rollers, it is evident that upon movementof the crosshead in the direction of the arrow 35, this is accompaniedby the simultaneous rotation of all the rollers according to the fullline arrows l3 and 48 respectively', and, upon movement in the directionof the arrow 56, a reverse rotation of the rollers will take place asshown by arrows 44 and 41 respectively.

One of the outstanding advantages of my small roller bearingconstruction (21 and 21') is that the rollersgradualiy move inconformity with the arrows 33 and M, consequently, any wear caused bythe outwardly acting piston loadwill tend to equalize itself bytransference of load and wear from the smaller rollers to the largeroller. It will be seen that due to the free and unrestrictedoperationof the rollers about their longitudinal axes they tend to uniformlydistribute wear, both on thecrosshe'ad engaging surfaces and on theneedle bearings and raceways thereof.

As above described, the entire stroke control mechanism 'or secondaryrotor is mounted in a completely antifriction bearing, and, I mayprovide for controlling the piston stroke and reversblocks 35 whichsupport said bearing ring and slide on appropriate bearing pads of thebody i.

when the stroke control assembly and the cylinder barrel are in theconcentric positions shown in Figs. 1 and 2, the entire pump mechanismrotates as one body. No reciprocation or relative motion takes placebetween the working parts of the pump, thus no fluid will be pumped inor out of the mains 23 and 24. When, however, the cylinder barrel andstroke control mechanism is shifted into eccentric relation, as shown inFigs. '7 and 8, the pistons reciprocate and will deliver acontinuousstream of fluid in a direction determined by the eccentricsetting of the, axis of the cheek plate and roller assembly at one sideor the other of the cylinder barrel axis.

It will be seen that I have substantially eliminated sliding frictionfrom the crosshead operating mechanism with consequent saving of powerand wear on the parts, thereby greatly increasing the efliciency of thistype of mechanism and making it possible to safely greatly increase therunning speed and output of the machine.

I claim:

1. In a rotary radial piston pump or motor of the character described,including a rotatable barrel, a series of circumferentially spacedradial cylinders therein, a valve pintle coaxial with the barrel and invalving cooperation with the cylinders, and pistons having T-heads andreciprocable in'the cylinders respectively, a reactance rotor eccentricto the pintle and surrounding the pistons and having radially extendingflanges disposed alongside the T-heads, load rollers respective to thepistons, each roller being antifrictionally mounted at its ends in thesaid flanges with its axis parallel to the pintle axis and spanning thespace between the flanges, and each roller being in rolling contactintermediate its ends with the outer surface of one of the T-headsnormally at the axis of the associated piston for oscillation therealongin both directions from. the axis of the piston associated therewith,and inner and outer torque transmitting rollers for each pistoncorrespondingly anti-frictionally mounted in the flanges for rollingcontact with the inner and outer surfaces respectively of the associatedT-head, one inner roller and one outer roller at each end portion of theT-head, whereby free 2. In a rotary radial piston pump or motor of thecharacter described, including a rotatable barrel, a series ofcircumferentially spaced'radial cylinders therein, a valve pintlecoaxial with the barrel and in valving cooperation with the cylinders,andpistons having T-heads and reciprocable radially in the cylindersrespectively, a reactance rotor eccentric to the pintle and surroundingthe pistons and having radially extending flanges disposed alongside theTheads, load rollers respective to the pistons, each roller beingrotatably mounted anti-frictionally at its ends in the said" flangeswith its axis parallel to the pintle axis and spanning the space betweenthe flanges, and each being in rolling con-; tact with the outer surfaceof one of the T-heads adjacent the axis of the piston associatedtherewith, and inner and outer torque transmitting rollers for eachpiston correspondingly antifrictionally mounted at their ends in theflanges and being in rolling contact with the inner and outer surfacesrespectively of the associated T- head, one inner roller and one outerroller at each end portion of the head, and anti-friction rollerbearings surrounding the ends of said rollers and anti-frictionallysupporting the same in said flanges, whereby positive torquetransmission is effected while maintainingfree tangential oscillation ofthe heads relative to the reactance rotor.

3. In a pump or motor of the character described, a rotatable barrelhaving a series of circumferentially spaced radial cylinders, valvemeans for the cylinders, radially reciprocable pistons received in thecylinders and having head portions at their outer ends extending foreand aft of their path of rotation, a reactance rotor surrounding saidpistons and eccentric to the barrel and having a pair of radial flangesaxially separable from each other and spaced apart to lie along oppositesides of the head portions, antifriction rollers having their axesextending parallel to the axis of said rotor, each of said rollershaving an enlarged central portion disposed between the flanges and inrolling contact with a portion of one of the piston head portions withwhich associated; and reduced diameter circumferentially recessed endportions defining radial shoulders at the ends of said central portion,aligned bores in said radial flanges for receiving the recessed endportions of the rollers axially and being of larger diameter than saidrecessed portions for accommodating cageless roller bearings insurrounding relation to said recessed portions and being of smallerdiameter than the central portion, and means to secure said flanges infixed axially spaced position with the recessed end portions of therollers so mounted in the bores and the said shoulders between thecentral portion and the end portions constraining the rollers againstaxial dislocation and the recessed portions and flanges confining saidneedle roller bearings against axial displacement a. In a rotary radialpiston pump or motor of the character described, including a rotatablebarrel, a series of circumferentially spaced radial cylinders therein, avalve pintle coaxial with the barrel and in valving cooperation with thecylinders, and pistons having T-heads and being 'reciprocable in thecylinders respectively, a reactance rotor eccentric to the pintle andsurrounding the pistons, inner and outer torque transmitting rollers foreach T-head, said rollers being carried by the reactance rotor andsecured thereby in fixed position circumferentially of the reactancerotor and having their axes parallel to the rotor axis, said rollersbeing in rolling contact with inner and outer surfaces respectively ofthe associated T-head, one inner roller and one outer roller at each endportion of the associated T+head, the axes of the inner and outerrollers at the same end of a T-head lying substantially in a planeparallel to the plane defined by the associated piston axis and the axisof revolution of the barrel, and load transmitting means carried by thereactance rotor and engaging the outer surfaces of the T-headsrespectively normally at the axis of the associated piston.

5. In a radial piston pump or motor of the character described includinga rotatable barrel, a radial cylinder therein, a valve pintle for thebarrel in valving cooperationwith the cylinder, a piston memberreciprocable radially in the cylinder, and a reactance rotor membereccentric to the pintle and surrounding the barrel, means for drivingsaid piston member on one stroke including a pair of axially separableradial flange portions on said rotor member spaced apart axially forreceiving snugly-therebetween the outer end portion of the pistonmember, a roller having its axis parallel to the pintle axis and havheadat the opposite end thereof concurrently,

ing an enlarged central portion disposed between and substantiallyspanning the space between the flanges and in driving relation to thepiston member for driving the same, and reduced diameter end portionsengaged with the flanges and defining with the central portion annularshoulders engaging the flanges for constraining the roller from axialdislocation, said roller being in rolling engagement with said pistonmember and having its axis fixed with respect to the reactance rotormember and being anti-frictionally mounted for rotation about its axisin said reactance rotor member.

6. In a rotary radial piston pump or motor of the character described,including a barrel having radial cylinders, a valve pintle in valvingcooperation with the cylinders, circumferentially spaced radial pistonscarried, thereby, a reactance rotor eccentric to the barrel forreciprocating the pistonsconsequent upon concurrent rotation of thebarrel and rotor, heads on the pistons respectively, each head extendingfore and aft of its path of rotation in each direction from the axis ofthe piston with which it is associated, means associated with the headsrespectively for transmitting torque from the pistons to the reactancerotor through the medium of said heads, each of said means comprisingapair of outer torque rollers journalled in the reactance rotor andspaced one in advance and one in the rear of the longitudinalmid-portion of the associated head, said rollers being journalled torotate about axes fixed with respect to the reactance rotor, acorrespondingly arranged and mounted pair of inner torque rollers, theouter rollers being cooperable with the outwardly facing surface of thehead and the inner rollers being cooperable with inwardly facingportions of the head, and load transmitting means carried by the rotorand engaging the heads respectively at the said mid-portions of the saidheads.

7. In a rotary radial piston pump or motor of the character described,including a barrel having radial cylinders, valve means for thecylinders, circumferentially spaced radial pistons carried thereby, anda reactance rotor eccentric to the barrel for reciprocating the pistonsconsequent upon concurrent rotation of the barrel and rotor, T-headsrespective to the pistons, each head extending fore and aft of its pathof travel in each direction from the axis of the piston with which it isassociated, sets of torque rollers antifrictionally mounted in thereactance rotor and having their axes parallel to the rotor axis, saidrollers being arranged one set to each head, one roller of each setbeing inrolling torque transmitting engagement with an outwardlydisposed face portion of the associated head at one end thereof, and theother roller being in rolling torque transmitting engagement with aninwardly disposed face portion of the associated cylinder member, one ofsaid members of each,

assembly having a head, axially separable radial flanges on the otherone' of said rotors spaced apart axially andaccommodatingtheheadstherebetween for tangential oscillation relativethereto, a plurality of anti-friction rollers having their axesextending parallel to the axis of rotation of the rotors, each of saidrollers having a relatively large diameter central portion disposedbetween the flanges and in rolling contact with one of said heads, andreduced diameter end portions defining radial shoulders at the ends ofthe central portion, aligned bores in said flanges receiving the reduceddiameter end portions of the rollers axially and being of largerdiameter than said end portions for accommodating elongatedcagelessroller bearings in surrounding relation to said reduced endportions, and being of smaller diameter than the central portion,elongated cageless roller bearings for the ends of the rollers, means tosecure said flanges in fixed axially spaced position with the reducedend portions of the rollers so mounted in the bores and said shouldersconstraining the roller bearings from inward axial displacement,and'means for constraining the roller bearings from outward axialdisplacement.

9. In a pump or motor of the character described, an inner rotor, anouter rotor, piston and cylinder assemblies carried by one rotor andreciprocable consequent upon concurrent rotation of the rotors, valvemeans for the cylinders, each assembly including a piston member and acylinder member, one of said members of each assembly having a head,axially separable radial flanges on the other one of said rotors spacedapart axially and accommodating the heads therebetween for tangentialoscillation relative thereto, a plurality of anti-friction rollers inoperative engagement with said heads respectively and having their axesextending parallel to the axis of rotation of the rotors, aligned boresin said flanges receiving the end portions of the rollers axially andbeing of larger diameter than said end portions for accommodatingelongated cageless roller bearings in surroundingrelation to said endportions, elongated cageless roller bearings for the ends of therollers, means to secure said flanges in flxed axially spaced positionwith the end portions of the rollers so mounted in the bores, and meansfor constraining the roller bearings from axial displacement.

10. In a rotary radial piston pump or motor of the character described,corotatable eccentric rotors, radial cylinders carried by one rotor,valve means therefor, pistons reciprocable in the cylindersrespectively, each piston having a head with a load transmitting surfaceextending fore and aft in the direction of rotation, a load transmittingroller for each piston anti-frictionally mounted at its ends in theother rotor for rotation about an axis fixed with respect to the saidother rotor and being in rolling load transmitting engagement with theload transmitting surface of the associated head substantially at theaxis of the piston, and means in addition to said load transmittingroller operatively connecting the head and the said other rotor foreffecting synchronous driving relation between the rotors.

11. In a rotary radial piston pump or motor of the character described,co-rotatable eccentric rotors, radial cylinders carried by one rotor,valve means therefor, pistons reciprocable in the cylindersrespectively, each piston having a head with a load transmitting surfaceextending fore and aft in the direction of rotation, rollers respectiveto the pistons and respectively anti-frictionally mounted in the otherrotor for rotation about an axis fixed with respect to the said otherrotor. said rollers being in rolling engagement each with an associatedpiston head and normally at the axis of the associated piston.

12. In a rotary radial piston pump or motor of the character described,a rotatable barrel; a series of circumferentially spaced radialcylinders therein; a valve pintle coaxial with the barrel and in valvingcooperation with the cylinders; pistons reciprocable in the cylindersrespectively; heads on said pistons respectively having radially innerand outer thrust-transmitting surfaces extending tangentially fore andaft of the respectively associated piston axes in the direction ofrotation of said barrel; a reactance rotor eccentric to the pintle andsurrounding the pistons; inner and outer torque-transmitting rollers foreach piston head, said rollers being carried by the reactance rotor andJ'oumalled therein to rotate about axes fixed eircumferentially withrelation to the reactance rotor and having their axes parallel to therotor axis, said rollers being in rolling contact with the inner andouter thrusttransmitting surfaces of the associated piston head, oneinner roller and one outer roller being at each end of the associatedpiston head; and load-transmitting means carried by the reactance rotorand engaging the outer surfaces or" the piston heads respectivelynormally at the axis of the associated piston.

13. In a rotary radial piston pump or motor of thecharacter described, arotatable barrel; a series of circumferentially spaced radial cylinderstherein; a valve, pintle coaxial with the barrel and in valvingcooperation with the cylinders; pistons reciprocable in the cylindersrespectively; heads on said pistons respectively having radially innerand outer thrust-transmitting surfaces extending tangentially fore andaft of the respectively associated piston axes in the direction ofrotation of said barrel; a reactance rotor eccentric to the pintle andsurrounding the pistons; inner and outer torquetransmitting rollers foreach piston head, said rollers being carried by the reactance rotor andjournalled therein to rotate about axes fixed cir= cumferentially withrelation to the reactance rotor and having their axes parallel to therotor axis, said rollers being in rolling contact with the inner andouter thrust-transmitting surfaces of the associated piston head, oneinner roller and one outer roller being at each end of the associatedpiston head, the axes of the inner and outer rollers at the same end ofa piston head lying substantially in a plane parallel to the planecontaining the associated piston axis and the axis of revolution of thebarrel; and loadtransmitting means carried by the reactance rotor andengaging the outer surfaces of the piston heads respectively normally atthe axis 0! the associated piston.

14. In a rotary radial piston pump or motor of the character described,including 'a barrel having radial cylinders, a valve pintle in valvingcooperation with the cylinders, circumferentially spaced radial pistonscarried thereby, a reactance rotor member eccentric to the barrel forreciprocating the pistons consequent upon concurrent rotation of thebarrel and rotor member, head members on the pistons respectively, eachhead member extending fore and aft of its path of rotation in eachdirection from the axis of rotation of the piston with which it is asso=ciated, means associated with the head members respectively fortransmitting torque from. the pistons to the reactance rotor memberthrough the medium of said head members, each of said means comprising apair of outer torque rollers journalled in one of said members andspaced one in advance and one in the rear oi the longitudinal midportionof the associated head member for rotation about axes fixed with respectto the member in which the rollers are journalled, a correspondinglyarranged and mounted pair of inner torque rollers, the outer rollersbeing cooperable with the outwardly facing surface oi the head memberand the inner rollers being co-= operable with the inwardly facingportions of the head member, and load-transmitting means car ried by therotor and engaging the head. members respectively at the midportionsthereot.

ELEK K. 13mm.

